February 12th Question
See Answer to February 5th Following Question
A 56-year-old man with ischemic cardiomyopathy, left ventricular ejection fraction 30%, New York Heart Association class III symptoms on optimal medical therapy, dual-chamber implanted cardioverter defibrillator in place, and chronic kidney disease stage 4 (creatinine clearance, 20 mL/min) presents to the office after 3 implanted cardioverter defibrillator shocks. Baseline ECG shows first-degree heart block and QRS duration 115 ms. He has a dual-chamber implanted cardioverter defibrillator. On device interrogation, all 3 episodes are similar; a representative episode is shown (Figures 1 and 2). What is the most appropriate next step?
A. Increase β-blocker
B. Increase lower rate limit
C. Start amiodarone
D. Arrange catheter ablation
E. Change pacing mode to DDD
Answer to February 5th Question
A. Left anterior descending coronary artery
The top left panel (Figure, right anterior oblique) shows the tip of the ablation catheter (ABL) to be close to the anterior free wall of right ventricular outflow tract. The top right panel (left anterior oblique) shows the ABL catheter tip pointing leftward and posteriorly toward the interventricular septum. The catheter is in the right ventricular outflow tract close to the anterior interventricular groove on the epicardial aspect between the right ventricular outflow tract and the base of the left ventricle. The proximal course of the left anterior descending artery runs in this groove, across the thin right ventricular outflow tract myocardium.1,2 The lower left (right anterior oblique) and lower right (left anterior oblique) panels in the Figure show spasm of the left anterior descending artery (arrows) noted on angiography performed after high-power ablation at this site.
Circ Arrhythm Electrophysiol is available at http://circep.ahajournals.org.
- © 2018 American Heart Association, Inc.